insect

Arthropod Monitoring Protocols

 

Click here for the ForestGEO Arthropod Monitoring Protocols.

Light Traps

We use 10 W black light traps (automatic bucket-type model) fitted with intercept panes and a roof protecting catches from rain (Kitching et al., 2001). Traps are filled with crumpled paper to provide surface to hold moths and other insects so that they do not lose most of their scales. Plastic, open egg trays separate larger insects from more fragile specimens. Insects are collected dry and killed by five strips of DDVP insecticide dispensed in the trap. The attraction range of one trap is < 50m (Baker & Sadovy, 1978).

Winkler

To concentrate and extract litter ants, mini-Winkler eclectors (Besuchet et al., 1987; Agosti, 2000) are used from a 0.25 m2 sample of leaf litter. The litter is picked up from within a 0.25m2 frame, concentrated with a litter sifter and stored into a cloth bag. Each replicate (sample) is calibrated with a 400ml cylinder randomly scooped up and hung in a mini-Winkler. The extraction of material lasts for 72 hours. Ants are collected in ethanol and then processed as required.

McPail Traps

McPhail traps (International Atomic Energy Agency, 2003; model from Biobest, www.biobest.be), baited with methyleugenol and cuelure are used to attract tephritid flies. The traps are running for a week and are set up in the vegetation, not in direct sunlight, at 3-4 m height. Attraction range of baits is < 100-200m (Cunningham & Couey, 1986).

Butterfly Transects

Walking transects of 500 m, timed to about 30 minutes (similar to Caldas & Robbins, 2003) are established to observe and catch butterflies. The observer restricts his/her attention to a 2 m wide strip across the transect and up to 5m height. For each transect, air temperature, relative humidity (%), and wind speed are also recorded. Cloudiness (%) is estimated visually. A full description of the protocol and how to implement it practically (establishment of local reference collection, etc.) is detailed in (Basset et al., 2013).

Termite transects

Termite sampling transects are destructive (wood fragmentation, soil disturbance, etc.) and therefore are performed outside the permanent plots. Each year, we sample one transect of 400m, including 1 quadrat of 5m2 searched for 30 minutes by one person, every 10m (total 40 samples; Roisin et al., 2006). This include 4 different operations: (a) inspection of all trunks and branches for termite galleries up to 2m in height; (b) breaking any dead logs and branches; (c) scooping 6 smaller soil samples of ca. 15x15x10 cm; and (d) stirring and inspecting most of litter within the quadrat.

Bee Baits

Cineole baits are used to attract euglossine bees traps (Ackerman et al., 1982; Roubik, 2001), dispensed in McPhail traps. The traps are baited with 7ml cineole and 100ml of commercial ethyleneglycol (car coolant) and run for a week.

Seed Predation

Non-rotting fruit and seeds from focal plant families are collected from inside and outside the plots. Fruits/seeds are processed as soon as possible after collection and placed in suitable rearing containers covered with black mesh and lined with tissue paper. Fruits of different species, tree individuals, collection sites, stage of maturity, size, and collection date are stored in separate rearing containers. Containers are checked a minimum of two times per week for emerging seed predators and parasitoids. Fruit/seeds are kept in a rearing shed for a period of three months. After this period, fruits/seeds are dissected before being discarded. In cases where developing larvae are encountered during dissection, fruits/seeds are returned to the rearing shed to allow for continued development of immature individuals. The protocol was adapted from (Janzen, 1980).

DNA Barcoding

Field arthropod samples are collected by placing a leg of each individual into vells of a microplate filled with 95% ethanol. The voucher specimen is dry mounted, pictured and preserved in a local reference collection. Vouchers are later transferred into collections of national importance in the host country. Sample preparation and DNA sequencing for arthropods are detailed in Wilson (2012; see also http://ccdb.ca/resources.php). Sequences and voucher pictures are gradually becoming all public at http://www.boldsystems.org/.