ENCYRTINAE

Noyes, John Stuart, 2023, ENCYRTIDAE OF COSTA RICA (HYMENOPTERA: CHALCIDOIDEA), 4 Subfamily Encyrtinae: tribes Arrhenophagini, Habrolepidini, Cerapterocerini, Cheiloneurini, Trechnitini, Cercobelini, Polaszekiini, Protyndarichoidini, Gahaniellini and Syrphophagini (part), mainly primary parasitoids and hyperparasitoids of Coccoidea and Psylloidea (Hemiptera), Taxonomic Monographs on Neotropical Hymenoptera (Oxford, England) 2 (11), pp. 1-921 : 6

BIOLOGY OF ENCYRTINAE

Excluding egg parasitoids, all species of Encyrtinae , for which biologies are known, are koinobiont endoparasitoids of other arthropods. Both gregarious and solitary parasitoids are known, and it is likely that very many species are facultatively gregarious, e.g. Metaphycus . More than 160 arthropod families are known to include hosts of Encyrtinae , although where they have been reared, about half have been reared from scale insects, in particular Coccidae and Diaspididae . Species of Ixodiphagus are well known parasitoids of ticks (Acari: Ixodidae ) and one species ( Globulencyrtus politus Hoffer ) has been reared from oribatid mites (Acari: Orobatidae). Most of the remaining recorded hosts belong to the holometabolous insect groups, mainly Lepidoptera , Diptera and Coleoptera . It is highly likely that encyrtids attacking these groups may be the most species-rich encyrtid groups in tropical forests. Hyperparasitoids are particularly common in the Encyrtinae with one tribe ( Cheiloneurini ) being largely composed of species that are hyperparasitic on encyrtids and other chalcidoid primary parasitoids of scale insects.

The biology, immature stages and development of the species of genera of Encyrtinae included in this study are dealt with in the relevant section of each genus. The host relationships of some of these genera as well as some others are summarised by Trjapitzin (1972a,b; Trjapitzin, 1989), Tachikawa (1974, 1978, 1981) and Noyes (1998, 2002, 2019).

The degree of host specificity of encyrtines is not known with any certainty but it appears that a good number of species can develop successfully in a variety of hosts. For instance, Metaphycus flavus (Howard) has been recorded from more than 35 species of soft scale hosts (see Guerrieri & Noyes, 2000) and Copidosoma floridanum (Ashmead) appears capable of parasitizing the immature stages of any species of plusiine noctuid ( Lepidoptera ) (see Noyes, 1988b; Guerrieri & Noyes, 2005). On the other hand, many species have been recorded from only one host species, but in most of these cases acceptance of other hosts or successful development within them has not been tested. However, it seems that most taxa of Encyrtinae have restricted host ranges with species attacking a particular group of hosts only. Groups that attack soft scales do not normally attack Lepidoptera and vice versa, although host shifts can occur in some groups. For instance, most species of Ooencyrtus are egg parasitoids of various groups of insects (mainly Hemiptera and Lepidoptera ), but some are primary parasitoids of caterpillars ( Lepidoptera ) or syrphid larvae ( Diptera : Syrphidae ), with one species even apparently parasitizing eggs of Hemiptera and pupae of chloropids ( Diptera : Chloropidae ) (see Noyes, 1985b, 2010). Finally, Syrphophagus includes species that are primary parasitoids of syrphid ( Diptera : Syrphidae ) larvae and other species that are hyperparasitoids of aphelinid or braconid parasitoids of aphids ( Hemiptera : Aphidae ).