Melittobia digitata dahms (hymenoptera: eulophidae) y monodontomerus mexicanus gahan (hym.: pteromalidae) on a nest of trypoxylon (trypargilum) mexicanum (saussure) (hym.: crabronidae) collected near Xalapa, Veracruz, Mexico

In a mud-nest built by Trypoxylon mexicanum, collected near Xalapa, Veracruz, Mexico, we recorded the presence of two parasitoids Monodontomerus mexicanus (Pteromalidae) and Melittobia digitata (Eulophidae), and one ant: Solenopsis geminata (Formicidae). The pteromalid is reported for the first time from Veracruz while the eulophid is reported from Mexico attacking another hymenopteran. The presence of an ant inside an empty cell is possibly just a coincidence.

Identification, Distribution, and Biology of Fire Ants in Texas.

25 p

Role of Ovarian Proteins Secreted by Toxoneuron nigriceps (Viereck) (Hymenoptera, Braconidae) in the Early Suppression of Host Immune Response

Toxoneuron nigriceps (Viereck) (Hymenoptera, Braconidae) is an endophagous parasitoid of the larval stages of the tobacco budworm, Heliothis virescens (Fabricius) (Lepidoptera, Noctuidae). During oviposition, T. nigriceps injects into the host body, along with the egg, the venom, the calyx fluid, which contains a Polydnavirus (T. nigriceps BracoVirus: TnBV), and the Ovarian Proteins (OPs). Although viral gene expression in the host reaches detectable levels after a few hours, a precocious disruption of the host metabolism and immune system is observed right after parasitization. This alteration appears to be induced by female secretions including TnBV venom and OPs. OPs, originating from the ovarian calyx cells, are involved in the induction of precocious symptoms in the host immune system alteration. It is known that OPs in braconid and ichneumonid wasps can interfere with the cellular immune response before Polydnavirus infects and expresses its genes in the host tissues. Here we show that T. nigriceps OPs induce several alterations on host haemocytes that trigger cell death. The OP injection induces an extensive oxidative stress and a disorganization of actin cytoskeleton and these alterations can explain the high-level of haemocyte mortality, the loss of haemocyte functionality, and so the reduction in encapsulation ability by the host

Evaluation of a Microbial Inhibitor in Artificial Diets of a Generalist Caterpillar, Heliothis virescens

Controlling microbial growth in artificial diets is a key component in the rearing of laboratory insects. In this study an antimicrobial agent, Diet Antimicrobial Agent (DAA), was tested for its ability to suppress microbial growth on a range of different diets, and for its effect on larval and pupal performance of individuals from two different strains of Heliothis virescens Fabricus (Lepidoptera: Noctuidae). In the first experiment, it was found that the presence of DAA in a pinto bean-based diet was highly effective at suppressing microbial growth relative to other methods, and that survival of caterpillars on diets with DAA was superior to other treatments. Caterpillars also performed best on diets with DAA, although this may have been the result of laboratory selection pressure as these caterpillars had been reared on pinto bean-based diets with DAA for several hundred generations. A second experiment was conducted, using different diets and a different strain of H. virescens to more fully evaluate DAA. Here it was found that DAA significantly suppressed microbial growth and development, particularly in synthetic diets. There was no significant effect of DAA on pupal development time or mass gain. There was a statistically significant effect of DAA on eclosion time for two of the diets, although the effect did not seem to be biologically meaningful. The findings suggest that DAA is an effective suppressor of microbial growth on artificial diets, and that its net effect on developing diet-reared insects is neutral

New species of Mesoplia (Hymenoptera, Apidae) from Mesoamerica.

36 p. : ill. (some col.) ; 26 cm.This paper investigates the bionomics of the cleptoparasitic bee Mesoplia sapphirina Melo and Rocha-Filho, sp. nov. (described in the appendix), and of its ground-nesting host Centris flavofasciata Friese found along the Pacific coast of Guanacaste Province, Costa Rica. We explore the host-nest searching behavior, egg deposition, and hospicidal behavior of M. sapphirina. Anatomical accounts of its egg, first, second, and fifth larval instars are presented and compared with published descriptions of other ericrocidine taxa. Nests of the host bee as well as its egg and method of eclosion are also described

Distribution and Abundance of Parasites of the Rhodesgrass Mealybug, Antonina graminis: Reassessment of a Classic Example of Biological Control in the Southeastern United States

Control of the rhodesgrass mealybug, Antonina graminis Maskell (Hemiptera: Pseudococcidae), by the encyrtid wasp Neodusmetia sangwani is considered a textbook example of classical biological control. However, recent evidence suggests that A. graminis is abundant in the southeastern United States and no recent surveys have been conducted to determine the status of N. sangwani or other A. graminis parasites. A survey was conducted and it was found that N. sangwani was uncommon overall, occurring at only 20 percent of survey sites. In addition, N. sangwani exhibited a patchy geographic distribution. Possible causes for these results are that N. sangwani has not dispersed widely since its introduction, or that the imported fire ant, Solenopsis invicta, is interfering with biological control. These results suggest that a reevaluation of the efficacy of biological control may be necessary. The survey also found two other encyrtid wasps utilizing A. graminis as a host. One, Acerophagus sp., is apparently native and was nearly as frequent as N. sangwani, while the other, Pseudectroma sp., is apparently introduced and relatively rare

Fire Ants and Their Management.

20 p