Walkymário de Paulo Lemos

Age-dependent fecundity and life-fertility tables for Podisus nigrispinus (Dallas) (Het., Pentatomidae)

Abstract: The reproductive potential and longevity of Podisus nigrispinus (Dallas) were determined under laboratory conditions at a constant temperature of 25°C. The data were used to calculate life‐fertility tables and rates of increase. The fecundity plateau of P. nigrispinus lasted 18 days, and during this period mean fecundity was 8.89 eggs per female per day. It started at the eighth day of age and ended at the 18th day of age. The declining fecundity period started at 18 days of age and ended with the death of the females. The female of P. nigrispinus oviposited a mean of 188.54 eggs, and had a mean longevity of 31.21 days. The gross reproductive rate (GRR) was 104.374 females/female; the net reproductive rate (Ro) was 31.945 females/female; the generation time was 47.390 days; the doubling time was 9.480 days; the intrinsic rate of increase (rm) was 0.073, and the finite rate of increase (λ) was 1.076. The predator population increased by 16.61 adult progeny per female per generation in the laboratory.

Effects of plant feeding on the development, survival and reproduction of Podisus nigrispinus (Dallas) (Heteroptera : Pentatomidae)

Diets consisting of leaves of cotton and/or water were insufficient to promote the complete development and survival of Podisus nigrispinus (Dallas) to the adult stage. However, nymphs fed leaves lived longer than those provided with only water. Addition of Alabama argillacea (Huebner) larvae to the diet of P. nigrispinus added a substantial increment to the survival during the nymphal stage. The addition of cotton leaves to the diet of P. nigrispinus nymphs promoted an increase in the weight of newly eclosed adults, independent of predator sex. In addition, diets supplemented with cotton leaves promoted an increase in the duration of the oviposition period, the number of egg clutches per female, and the number of eggs per female. No effects were noted on either the duration of the pre-oviposition period, the number of eggs of the first clutch, the number of eggs per clutch, the interval between egg clutches, or sex ratio. Feeding on plant material by P. nigrispinus is a potentially positive attribute in biological control against cotton leafworm.

Lethal and sub-lethal selectivity of fenbutatin oxide and sulfur to the predator Iphiseiodes zuluagai (Acari: Phytoseiidae) and its prey, Oligonychus ilicis (Acari: Tetranychidae), in Brazilian coffee plantations

Lethal concentration (LC) has been widely used to estimate pesticide toxicity. However, it does not consider the sub-lethal effects. Therefore we included the instantaneous rate of increase in association with LC to estimate population-level effects of the acaricides fenbutatin oxide and sulfur on the predator Iphiseiodes zuluagai and its prey, the phytophagous southern red mite, Oligonychus ilicis. The predator was 32.84x and 17.20x more tolerant to fenbutatin oxide and sulfur, respectively, than its prey, based on LC50 estimates obtained from acute concentration–mortality bioassays. The instantaneous rate of population growth in both mite species decreased with increasing acaricide concentration. Both acaricides provided effective control of O. ilicis at their recommended concentrations, but sulfur drastically compromised the predator populations quickly leading them to extinction due to the low reproductive potential of this species compared with its prey.

Effects of diet on development of Podisus nigrispinus (Dallas) (Het., Pentatomidae), a predator of the cotton leafworm

Abstract:  The effects of diet on development of Podisus nigrispinus (Dallas) (Het., Pentatomidae) were studied at 25°C, relative humidity of 60 ± 10%, and photoperiod of 14 h light : 10 h dark. Development times of P. nigrispinus nymphs were similar when fed with third or fifth instar larvae of cotton leafworm (Alabama argillacea Hübner) (Lep., Noctuidae) or Tenebrio molitor L. (Col., Tenebrionidae). When fed with housefly larvae (Musca domestica L.) (Dipt., Muscidae) or artificial diet, the predator had a longer development time. Independent of diet, instar or sex, the females of P. nigrispinus showed a longer longevity than the males. The total survival of the nymphal stage, on the different diets, varied from 22.46 (fed with housefly) to 77.33% (fed with T. molitor larvae). P. nigrispinus males were heavier when fed with third or fifth instar cotton leafworm larvae than when fed with artificial diet. The weight of the females varied from 37.91 (with artificial diet) to 64.68 mg (with fifth instar cotton leafworm larvae). Independently of the diet, newly emerged females of P. nigrispinus were heavier than the males. Females of P. nigrispinus which were fed with fifth instar cotton leafworm larvae had heavier ovaries than those fed other diets.

Morphology of female reproductive tract of the predator Podisus nigrispinus (Dallas) (Heteroptera: Pentatomidae) fed on different diets

Este estudo apresenta a morfologia do sistema reprodutor feminino de Podisus nigrispinus (Dallas) alimentado com larvas de Alabama argillacea (Hubner), Musca domestica L. e de Tenebrio molitor L. ou dieta artificial. As gonadas internas desse predador apresentaram coloracao amarelada e, independente da dieta, cada ovario apresentou sete ovariolos unidos pelos filamentos terminais em uma estrutura em forma de cacho. A analise histologica revelou que o ovario de P. nigrispinus e do tipo meroistico telotrofico com cada ovariolo dividido morfologicamente em filamento terminal, trofario (câmara nutridora), vitelario e pedicelo. A dieta recebida por esse predador alterou o desenvolvimento e a morfometria de seus ovarios. Femeas de P. nigrispinus alimentadas com larvas de terceiro ou quinto estadio de A. argillacea apresentaram ovarios desenvolvidos com grande numero de ovocitos em estagio avancado de desenvolvimento nos ovariolos. Femeas com dieta artificial apresentaram ovarios atrofiados e ovariolos, praticamente, sem ovocitos em seu interior enquanto aquelas alimentadas com larvas de T. molitor ou M. domestica tiveram ovarios em estagios intermediarios de desenvolvimento. O comprimento do ovariolo central foi maior em femeas alimentadas com larvas de quinto estadio de A. argillacea e menor naquelas com dieta artificial. Ovocitos em estagios mais avancados de desenvolvimento foram observados para femeas alimentadas com larvas de terceiro ou quinto estadios de A. argillacea, enquanto ovocitos atrofiados foram observados para aquelas com dieta artificial.

Age-dependent fecundity and fertility life tables of the predator Brontocoris tabidus (Heteroptera: Pentatomidae) under field conditions.

Reproductive potential, longevity, life expectancy, and fertility life tables of Brontocoris tabidus (Signoret) (Heteroptera: Pentatomidae), a predator of lepidopteran defoliators in eucalyptus (Eucalyptus spp.) plantations, were studied in the field. After a 50-d preoviposition period (emergence of adults to the deposition of the first egg mass), ovipositional activity of B. tabidus continued until females died at 160 d. Females laid an average of 4.2 eggs per day and 601.1 eggs in a lifetime. Gross and net reproductive rates were 216.7 and 75.8 females, respectively. Generation time was 146.1 d, the period for doubling the population was 23.4 d, intrinsic rate was 0.03, and finite population increase was 1.03. Number of females per generation increased at 33.4 times. Results from our field studies indicate that B. tabidus has greater potential reproduction, oviposition period, and longevity than was expected from previous laboratory experiments. This suggests that B. tabidus has potential as a biological control agent to limit economically damaging pests in eucalyptus plantations.

Attack behavior of Podisus rostralis (Heteroptera: Pentatomidade) adults on caterpillars of Bombyx mori (Lepidoptera: Bombycidae)

Attack behavior of the predator Podisus rostralis (Stal) (Heteroptera: Pentatomidae) adults on fourth instar Bombyx mori L. (Lepidoptera: Bombycidae) caterpillars was studied in laboratory conditions. Ten 24 hours old adults of this predator were observed during two hours with the following attack behavior: (1) Predator: prey finding; prey observation; touching prey with antenna; attack behavior; prey paralysis; predator retreat after attack; attack cessation; successive attacks; and (2) Prey: defense. The predator P. rostralis found its prey before attacking and it approached it with slow circular movements. The attack was usually made in the posterior part of the prey to reduce defense reaction. Larger size of prey in relation to the predator resulted difficult prey paralysis but it occurred in less than two hours.

Effect of diet on male reproductive tract of Podisus nigrispinus (Dallas) (Heteroptera: Pentatomidae)

The morphology and histology of the reproductive tract of males of the predator Podisus nigrispinus (Dallas) fed on different diets were studied. P. nigrispinus was fed on diets of: larvae of Alabama argillacea (Hübner), Tenebrio molitor L., Musca domestica L., and an artificial diet. The male reproductive tract, independent of diet, showed testes with intense red coloration in a compact, circular, or slightly oval structure. The vasa deferentia were similar in color to the testes and formed long filaments, which joined with the yellow-cream colored ejaculatory duct. The morphological characteristics of the male reproductive tract were similar under all diets, except for the artificial one. The histological studies demonstrated that independent of the diet the testes of P. nigrispinus were composed of four to six follicles. The testes with six follicles generally had four developed and two atrophied follicles. The morphological and histological differences of the testes of P. nigrispinus when fed with different prey are presented and discussed.

Body weight and protein content in the haemolymph of females of the zoophytophagous predator Brontocoris tabidus (Heteroptera: Pentatomidae) with different diets and ages

The effect of different diets [1. Tenebriomolitor L. (Coleoptera: Tenebrionidae) pupae; 2. T. molitor pupae and Eucalyptus cloeziana plants; 3. T. molitor pupae and Eucalyptus urophylla plants; and 4. T. molitor pupae and guava plants (Psidium guajava L.)] on the body weight and the protein content of haemolymph of Brontocoris tabidus (Signoret) (Heteroptera: Pentatomidae) females were analyzed. Fifteen days old females of B. tabidus were heavier on plants and T. molitor pupae than only with pupae of this prey. Twent-one days old females of this predator were heavier with E. cloeziana or guava plants and lower with E. urophylla and T. molitor pupae or only with pupae of this prey. The body weight of 15 and 21 days old females of B. tabidus was similar in most treatments and lower with E. urophylla and T. molitor pupae. Fifteen days old females of this predator were heavier when fed on T. molitor pupae and guava plants than those 21 days old. The protein content in the haemolymph of females of this predator was similar in all diets and ages. The phytophagy increased the body weight, but not the protein content in the haemolymph of females of the predator B. tabidus.ZusammenfassungDer Einfluss verschiedener Diäten [1. Puppen von Tenebrio — molitor L. (Coleoptera: Tenebrionidae), 2. T. molitor -Puppen und Eucalyptus cloeziana, 3. T. molitor -Puppen und Eucalyptus urophylla sowie 4. T. mo l it or-Puppen und Guavenbäume (Psidium guajava L.)] auf das Körpergewicht und den Protein- gehalt der Hämolymphe von Weibchen der Raubwanze Bron- tocoris tabidus (Signoret) (Heteroptera: Pentatomidae) wurde untersucht. Fünfzehn Tage alte Weibchen der Raubwanze waren schwerer in Gegenwart von Pflanzen und T. molitor - Puppen als nur mit den Puppen als Nahrung. Einundzwanzig Tage alte Weibchen waren schwerer in Gegenwart von E. clo- eziana oder Guavenpflanzen alleine und leichter mit E. uro- phylla und T. m o l it or -Puppen oder nur mit den Käferpuppen. Das Gewicht der 15 und 21 Tage alten Wanzenweibchen unterschied in den meisten Varianten nicht, war aber geringer in den Varianten mit E. urophylla und T. molitor -Puppen. Fünfzehn Tage alte Weibchen waren schwerer als 21 Tage al- te, wenn ihnen T. molitor und Guavenpflanzen zur Verfügung standen. Der Proteingehalt der Hämolymphe der Wanzenweib- chen war bei allen Nahrungs- und Altersvarianten ähnlich. Die Phytophagie erhöhte zwar das Körpergewicht der räuberischen Wanzen, nicht aber den Proteingehalt der Hämolymphe.

Age-Dependent Fecundity and Life-Fertility Tables for Euborellia annulipes (Lucas) (Dermaptera: Anisolabididae) a Cotton Boll Weevil Predator in Laboratory Studies with an Artificial Diet

Abstract Little information regarding the biology and ecology of dermapteran predators has been reported. For possible use of Euborellia annulipes (Lucas) (Anisolabididae) in biological control programs against the cotton boll weevil Anthonomus grandis grandis Boheman (Curculionidae), it is important to know the effect of temperature on reproduction in this predator. Our objective was to evaluate the reproductive potential and the longevity of females of E. annulipes under laboratory conditions using an artificial diet, at 25 and 30°C, and to estimate life-fertility tables and growth rates. Fecundity began to decline on day 84 at 25°C and on day 74 at 30°C of adult age and ended with the death of the females at both temperatures. Females of E. annulipes oviposited an average of 206 and 306 eggs, and had a mean longevity of 198 and 149 d at 25 and 30°C, respectively. The gross reproductive rates were 89.2 at 25°C and 91.4 at 30°C; the net reproductive rates were 65.3 at 25°C and 40.3 at 30°C; the generation times were 195.2 d at 25°C and 142.9 d at 30°C; the doubling time was 33.0 d at 25°C and 26.7 d at 30°C; the intrinsic rates of increase were 0.02 at 25°C and 0.03 at 30°C, and the finite rates of increase were 1.02 at 25°C and 1.03 at 30°C. The predator population increased by 52 at 25°C and 20 at 30°C adult progeny per female per generation in the laboratory. The best age for inoculative releases of E. annulipes against cotton boll weevil populations is the age with the highest age-specific reproductive values, that is, newly emerged females at 25 or 30°C.