Bacteria associated with the intestinal tract of three predators of Dactylopius opuntiae (Hemiptera: Dactylopiidae)

Abstract

Insects depend on gut bacteria for many metabolic functions including detoxification. Dactylopius (Hemiptera: Dactylopiidae) species (e.g. D. opuntiae and D. coccus) produce carminic acid possibly acting as part of their immune response to predation; thus predators of Dactylopius species may require intestinal symbionts to metabolize carminic acid acquired from their prey. The average content of carminic acid in D. opuntiae and D. coccus is 3–5% and 19–25% respectively; the predators Leucopina bellula and Hyperaspis trifurcata are specialists on D. opuntiae while Laetilia coccidivora feeds on both D. opuntiae and D. coccus. We determined the diversity of bacteria associated with the gut of these predators to test the hypothesis that it would vary significantly depending on the level of prey specialism. Bacteria were isolated from the intestine of Le. bellula, L. coccidivora and H. trifurcata larvae and also adults of H. trifurcata. Bacteria were identified morphologically and by partial sequencing of the 16S rRNA gene. The greatest bacterial diversity was found in L. coccidivora and H. trifurcata adults, followed by H. trifurcata larvae. The lowest diversity was found in Le. bellula. Sequencing revealed the presence of Bacillus cereus, Enterococcus gallinarum and E. casseliflavus in L. coccidivora larvae; Enterobacter sp. in larvae of H. trifurcata; Lactococcus lactis in adults of H. trifurcate; and Staphylococcus sp. in larvae and adults of H. trifurcate. Bacillus pumilus was only found in Le. bellula. The possible role of these bacteria in the ability of predators to feed on D. opuntiae and D. coccus is discussed.