Thomas C. Emmel

DEMOGRAPHY OF GREGARIOUSLY ROOSTING POPULATIONS OF THE NYMPHALINE BUTTERFLY MARPESIA BERANIA IN COSTA RICA

Populations of the daggerwing butterfly, Marpesia berania (Hewitson) (Nymphalidae; Nymphalinae), assemble nightly in roosts of up to 68 individuals in the tropical rain forest of the Osa Peninsula, Costa Rica. Gregarious nocturnal roosting in butterflies in uncommon, and reported almost exclusively in supposedly distasteful species. We studied two roosts, using a marking technique that permitted visual censusing. The butterflies maintained roosting sites in the same general locations and regularly returned to them before evening, during life spans of over 5 months. The sex ratio was unity, and the rates of population recruitment and mortality were apparently the same for both sexes. The instantaneous mortality rates were approximately 0.0126 (on a daily basis) over the study period, and the recruitment rates for the two roosts were 0.907 and near 0.15 butterfly per day for March and April, 1968 (the last month of the dry season and the first month of the wet season). In the following 3 months of the wet season, recruitment decreased to near zero. The empirically determined rates of recruitment and mortality accurately predicted the initial population size, indicating that the adult population was under equilibrium conditions during the dry season and the first month of the wet season.

Selection and Host Overlap in Two Desert Papilio Butterflies

The two California desert Papilio (Lepidoptera: Papilionidae) species, P. indra fordi Comstock & Martin and P. rudkini Comstock, are frequently sympatric in range but mutually exclusive in host plant source. In 1966, optimal rainfall conditions led to a large simultaneous emergence of the adults of both species, synchronizing the growth of the resulting larvae, and larvae of both species switched to feeding on both foodplants wherever defoliation of the usual foodplant had already occurred from earlier larval feeding. By feeding on different foodplants in years of normal population levels, larval competition is avoided and many host plants remain unused. But apparently when population peaks are reached simultaneously, the selective advantage of separate hosts breaks down and direct competition through foodplant overlap occurs. See full-text article at JSTOR

Quantitative analysis of pheromone production in irradiated Caribbean fruit fly males,Anastrepha suspensa (Loew)

Pheromonal volatiles emitted by irradiated and control 5- to 11-day-old Caribbean fruit flies,Anastrepha suspensa (Loew), were collected on Tenax adsorbent filters and quantified by gas chromatography (GC). The components released were identified by comparison of retention times on GC and by mass spectrometry (MS) with authentic synthetic standards. Pharate adults were irradiated with gamma rays from a60Co source at a dose rate of 10.3 Gray (Gy)/min. The total dosages given were 30, 50, 70, and 100 Gy. Pheromone volatiles were collected from adult males when they were between 5 and 11 days of age. The compounds quantified were (Z)-3-nonenol and (Z, Z)-3,6-nonadienol, which eluted from the GC column together and were quantified as one peak,β-bisabolene, suspensolide, anastrephin, and epianastrephin. Irradiation with 30 Gy did not significantly reduce any pheromonal components, nor did it change the pheromonal blend. In contrast, suspensolide and bisabolene were significantly reduced in flies irradiated with 50 Gy, while the nonenols and epianastrephin were reduced at the 70-Gy dose. Irradiation with the 100-Gy dose reduced all components with the exception of suspensolide.

Veterinary Pediatrics of Butterflies, Moths, and Other Invertebrates

In the life cycle of invertebrate animals, the typical life history includes the egg and larval stage, which may be called the pediatric phases, representing development up to the point where the animal reaches adulthood with fully functional reproductive organs and full adult characteristics of morphology, coloration, physiology, and behavior. These typical immature or pediatric stages are found in both terrestrial and aquatic invertebrates. This article reviews the factors that impact the health and survival of juvenile stages of butterflies and moths in particular, and what can be done to extend veterinarian care and advice to clients to invertebrate problems.