Using Visible Implant Elastomer to tag insects across life stages: a preliminary investigation with blow flies (Diptera: Calliphoridae)

Visible Implant Elastomer (VIE) has previously been used successfully to tag individuals in a variety of marine and amphibious animals, earthworms, and scorpions. Visible Implant Elastomer tags were injected into third instars of the blow fly Calliphora vicina Robineau-Desvoidy (Diptera: Calliphoridae) to test its compatibility and retention across life stages. Injecting into the dorsal midline of the 11th segment (seventh abdominal segment) produced survival rates of 80%, with no significant difference in the subsequent rate of development (z = 0.21, P = 0.83) as compared with untagged insects. Tags remained visible and allowed identification of individuals within a feeding, intermingling aggregation (maggot mass), especially when a high-contrast fluorescent colour was used. Tags were retained across life-stage changes and were easily found in dissected adults.

Changes in Development and Heat Shock Protein Expression in Two Species of Flies (Sarcophaga bullata [Diptera: Sarcophagidae] and Protophormia terraenovae [Diptera: Calliphoridae]) Reared in Different Sized Maggot Masses

Development of two species of necrophagous flies, Sarcophaga bullata Parker (Sarcophagidae) and Protophormia terraenovae (Robineau-Desvoidy) (Calliphoridae), was examined in different size maggot masses generated under laboratory conditions. Larvae from both species induced elevated mass temperatures dependent on the number of individuals per mass. The relationship was more evident for S. bullata, as larvae generated higher temperatures in every size maggot mass than P. terraenovae. Several development events were altered with increasing maggot mass size of flesh flies, and to a lesser extent blow flies, which corresponded with elevated temperatures. Duration of development of all feeding larval stages decreased with increased size of maggot mass. However, the length of development during puparial stages actually increased for these same flies. Puparial weights also declined with maggot mass size, as did the ability to eclose. The altered fly development was attributed to the induction of heat stress conditions, which was evident by the expression of heat shock proteins (23, 60, 70, and 90) in larval brains of both fly types.