Adrián J. Molina-Rugama

Functional response of the predator Eriopis connexa (Coleoptera: Coccinellidae) to different prey types

This work evaluated the functional response of adult females of Eriopis connexa to different densities of Macrosiphum euphorbiae and Tetranychus evansi. When preying upon aphids, E. connexa presented a sigmoidal functional response (Type III). This behavior, however, changed drastically to an exponential (Type II) functional response, when mites (T. evansi), rather than aphids, were offered to E. connexa. Such different patterns showed that this coccinellid needed to adopt distinct strategies according to the kind of prey available. Since predators were believed to be able to regulate prey populations only when adopting Type III functional response. E. connexa would be a good candidate for a biological control agent of M. euphorbiae, but would not suppress a growing population of T. evansi.

Nymphal Development and Reproduction of Podisus nigrispinus (Heteroptera: Pentatomidae) Fed With Combinations of Tenebrio molitor (Coleoptera: Tenebrionidae) Pupae and Musca domestica (Diptera: Muscidae) Larvae

The development and reproduction of Podisus nigrispinus (Dallas) (Heteroptera: Pentatomidae) fed on Tenebrio molitor L. (Coleoptera: Tenebrionidae) and Musca domestica L. (Diptera: Muscidae) were studied in four treatments. P. nigrispinus was permitted to feed on: (1) T. molitor pupae (T 1 ); (2) Musca domestica larvae (T 2 ); (3) both prey supplied simultaneously (T 3 ); (4) both prey supplied on alternate days (T 4 ). Duration of the nymphal period of P. nigrispinus was similar in all diets studied with nymphal viability of approximately 75%. Heavier females were obtained in T 1 and T 4 , but no correlation between this factor and the reproductive rate of the predator was found. Therefore, the use of body weight as a parameter to evaluate rearing quality should be approached with caution. However, females of this predator showed higher egg and nymph production when they received both prey. For this reason P. nigrispinus should be reared with T. molitor and M. domestica simultaneously or on alternate days.

Reproductive strategy of Podisus rostralis (Stal) (Heteroptera: Pentatomidae) females under different feeding intervals

The reproduction and survival of Podisus rostralis was evaluated under different feeding intervals using Tenebrio molitor larvae as food and a continuous supply of bean slices. There was a linear r...

Efeito do peso corporal na fecundidade e na longevidade do percevejo predador Podisus rostralis

(4) Abstract - Considering the importance of predatory Pentatomidae as biological control agents it is necessary to optimize mass production facilities of these species. The objective of this research was to evaluate the influence of body weight on survival and reproductive parameters of females of Podisus rostralis (Stal) (Hemiptera: Pentatomidae). Treatments were represented by females of this predator with the following mean weight: 39.5 mg, 45.5 mg, 51.5 mg, 57.5 mg and 63.5 mg. Heavier females of P. rostralis showed shorter preoviposition period while the number of eggs and of nymphs per day presented a positive linear relationship with female weight of this predator. Longevity of females of P. rostralis was similar between treatments with no tendency of variations as a function of body weight of these females. Since the objective of mass rearing facilities of predatory bugs is to produce the maximum possible number of nymphs per day it is recommended to use females of P. rostralis with weight above 60.0 mg.

Predatory behaviour of Podisus nigrispinus (Heteroptera: Pentatomidae) on different densities of Anticarsia gemmatalis (Lepidoptera: Noctuidae) larvae

Abstract The functional response of the predatory bug Podisus nigrispinus (Dallas) (Heteroptera: Pentatomidae) feeding on its prey, Anticarsia gemmatalis Hübner (Lepidoptera: Noctuidae), was studied in a greenhouse compartment. Each cage enclosed three soybean plants plus two, four, six, eight, 10, 12 or 14 prey larvae. One adult predator was released and kept inside the cages for 24h. The predation rate of adult male P. nigrispinus was highest at densities of eight or more A. gemmatalis larvae with a handling time of 5.76h and an attack rate of 0.68h−1. Adult females had higher predation rates on plants with 10 or more A. gemmatalis larvae, with a handling time of 3.84h and an attack rate of 0.65h−1. The maximum number of larvae consumed by males and females of this predator were 4.1 and 6.0 per day, respectively, in groups of three plants. The results suggest that P. nigrispinus may be used in biological control programmes against A. gemmatalis in soybean fields.

Reproduction and longevity of Supputius cincticeps (Het.: Pentatomidae) fed with larvae of Zophobas confusa, Tenebrio molitor (Col.: Tenebrionidae) or Musca domestica (Dip.: Muscidae)

Reproduction and longevity of Supputius cincticeps (Stal) (Heteroptera: Pentatomidae) fed on Zophobas confusa Gebien, Tenebrio molitor L. (Coleoptera: Tenebrionidae) or Musca domestica (L.) (Diptera: Muscidae) larvae were studied during two generations at 24.7 ± 1.1oC, 70 ± 10% R.H. and 12 h of photophase. Body weight of newly-emerged adults, oviposition period, number of egg masses, total number of eggs and longevity of S. cincticeps were higher when fed on Z. confusa or T. molitor larvae than on M. domestica larvae. Regardless of diet, S. cincticeps showed better reproduction and longevity in the second generation in laboratory conditions.

Efeito do intervalo de alimentação na reprodução e na longevidade do predador Podisus nigrispinus (Dallas) (Heteroptera: Pentatomidae)

The effect of feeding intervals on Podisus nigrispinus (Dallas) (Heteroptera: Pentatomidae) females was studied. Females were fed during 24 hours after either one, two, four, eight or 16 days with Musca domestica L. (Diptera: Muscidae) larvae at 24 ± 3o C, 70 ± 10% RH and photophase of 12 hours. Females of P. nigrispinus fed every one, two and four days produced higher number of eggs (225.4, 184.6 and 135.3 eggs, respectively) than those fed every eight or 16 days (8.3 and 0.0 eggs, respectively). Females fed every four days lived longer (43.0 days) than those fed every eight or 16 days (27.3 and 10.6 days).

Efeito da escassez de presa na sobrevivência e reprodução do predador Supputius cincticeps (Stål) (Heteroptera: Pentatomidae)

The effect of prey shortage on the performance of Supputius cincticeps (Stal) females was evaluated at 24.6 ± 0.7oC, 80 ± 4% RH and 12h photophase. Larvae of Tenebrio molitor L. were offered to the females during 24h every one, two, four, six or eight days; pieces of green bean (Phaseolus vulgaris L.) were offered continuously. The percentage of females with egg masses, oviposition period, and the number of egg masses, eggs and nymphs decreased with the increase in the interval without prey, whereas the periods of pre- and pos-oviposition increased. On the other hand, longevity and number of eggs per egg mass were not affected by the prey regimen. The results suggest a trade-off between longevity and fecundity (reduction of fecundity to maintain longevity), which could contribute to the establishment and survival of S. cincticeps during periods of prey scarcity.

Dados biológicos de Podisus nigrispinus (Dallas) alimentado com a lagarta do maracujazeiro Dione juno juno (Cramer)

Survival and life cycle of Podisus nigrispinus (Dallas) (Heteroptera: Pentatomidae) fed Dione juno juno (Cramer) (Lepidoptera: Heliconiidae) larvae were studied at 25 ± 2°C, 65 ± 10% RH and 12 h D:L. Duration of egg stage and of 1st, 2nd, 3rd, 4th and 5th stadia was 4.0; 4.0; 4.9; 4.7; 4.8 and 5.8 days, respectively. Survival from 1st instar to adult stage was 67%. The predator took 28 days and the prey 33 days to complete the life cycle.

PREFERÊNCIA DE CORTE DE Eucalyptus spp. POR Acromyrmex laticeps nigrosetosus FOREL, 1908 (HYMENOPTERA: FORMICIDAE) EM CONDIÇÕES DE LABORATÓRIO

The objective of this research was to evaluate the cutting preference of Acromyrmex laticeps nigrosetosus workers among three species and a Clone of eucalypt. The seedlings of Eucalyptus spp. were offered simultaneously to three colonies of this leaf-cutting ant under laboratory conditions. The assay ended six hours after initial offering or until the workers of a colony cut all leaves of a certain eucalyptus species. On the average, colonies cut and carried 0.453g ± 0.064 of Eucalyptus camaldulensis ; 0.384g ± 0.052 of Clone 129; 0.341g ± 0.054 of Eucalyptus urophylla and 0.102g ± 0.027 of Eucalyptus cloeziana . This last species was the least preferred for cutting and carrying. On the other hand, there was no significant difference among the amount of leaves cut from the other eucalypts.