The UCR Collection of Aphytis

The UCR collection of Aphelinidae is historically one of the most important worldwide collections for this group. It is based on material of P. Timberlake, C.P. Clausen, H. Compere and P. DeBach and associated with their foreign exploration of natural enemies for citrus and other crop pests. About 40,000 slide-mounted specimens of Aphelinidae are housed in the collection with the largest holdings in economically important genera such as Aphytis (3,780 slides with determined specimens, 600 miscellaneous), Coccophagus (1140 determined, 520 undetermined), and Encarsia (3000, mostly undetermined). In addition, the pinned collection houses material for 24 genera and 137 determined species and numerous undetermined specimens. In North America the only other important collections of Aphelinidae are at the National Museum of Natural History (about 40 drawers of slides and pointed specimens including 5 drawers of pinned and slide-mounted [ca. 750 slides] material of non-type Aphytis belonging to 28 species) and Texas A&M University (ca. 2500 slides, mostly Eretmocerus and Encarsia). Most aphelinids in the Canadian National Collection are point-mounted and only a few are slide-mounted. Worldwide, the most important collections are at The Natural History Museum, the Queensland Museum, Aligarh Muslim University and the University of Naples.

The UCR collection of Aphytis (Table 3) has no parallel in the world considering the number of determined specimens belonging to 87 valid species (ca. 24,000 of ca. 30,000 slide-mounted individuals), almost all of which were reared from known hosts and/or are vouchers of past or ongoing biological control programs at UCR and elsewhere. Many of these voucher specimens represent cultures of species imported into the UCR Quarantine facility and released in the United States since the 1930's.

Before 1996, the UCR collection of Aphytis was difficult to access because of its poor organization -- slides were scattered among the Hymenoptera collections and mixed with other Aphelinidae and Encyrtidae in various slide boxes. In 1996, the entire Aphytis slide collection was reorganized by Serguei Triapitsyn. Determined specimens are now stored in six slide cabinets, each able to store up to 2,000 slides, and organized alphabetically. In addition, all undetermined Aphytis slide-mounted specimens (on 825 slides) were grouped together in nine regular slide boxes (each capable of holding 100 slides).

Unfortunately, the physical condition of the majority of these specimens can be described as very poor, primarily due to the use of an improper mounting technique described in Rosen & DeBach (1979). Their choice of Hoyer's as a mounting medium and of Zut(Æ) as the primary ringing compound was a disastrous one (Upton 1993). Most of the Hoyer's mounts, especially those rung with Zut(Æ), are now completely or partially dry (see Fig. 1). A few slides rung with Glyptal(Æ) are in slightly better condition but these also have the potential for future breakdown (Upton 1993). In addition, slides mounted in Hoyer's medium often become dark with age (Fig. 1). Upton (1993) demonstrated that water soluble media such as Hoyer's are not suitable for mounting specimens intended for long-term storage and use in taxonomic collections. Earlier, Schauff (1985) criticized the mounting technique used for the Aphytis spp. type material and pointed out that their proper storage and curation will be difficult.

The number of slides requiring remediation is summarized in Table 1. In addition, the primary types of the species described by P. DeBach and D. Rosen, now on permanent loan from UCR to USNM, also require remediation. We are remediating these primary types and other type material on permanent loan to USNM. Thus, the majority of the type and non-type material will be remounted from Hoyer's into Canada balsam. This task, which is as costly and time consuming as any slide-mounting can be, becomes even more difficult considering the other major mistakes made in the course of original mounting as follows: 1) poor label data or occasional presence of only code (catalog) numbers (which are lost) or Quarantine S & R numbers (which thankfully in most cases can be found in UCR Quarantine files); 2) presence of several (often up to 100) specimens on the same slide under one or several coverslips (Fig. 1c); 3) presence of several species under the same coverslip (cf. Fig. 1b); and 4) some labels have peeled off and become disassociated from the slides.

All of the type material (347 slides/1530 specimens at UCR) and the majority of the identified material (3,780 slides/16,000 specimens) are in the process of complete remediation and curation. Some species, for instance A. lingnanensis or A. melinus, together comprise about 7,000 specimens; of these only a part will be selected for remediation since there are many duplicates in the collection. These can be remounted at a later date if necessary. However, all voucher specimens as well as specimens from exotic locations must be remounted.