Post-harvest insect pest directory
Species of Ptininae
Scientific name: Ptininae
- Order
- Coleoptera
- Classification
- Secondary
- Incubation at 20 C
- 10-14 days
- Incubation at 30 C
- 5-7 days
Description
Adults of Ptininae are minute beetles (2–4.5 mm) with a distinctly spider‑like habitus. In dorsal view the head is entirely, or almost entirely, concealed. Coloration is variable, and the integument may be glabrous or finely pubescent. Antennae and legs are conspicuously elongate, enhancing the arachniform appearance. Larvae are white and vermiform, with a well‑developed head capsule and functional thoracic legs.
Detection
Key signs of infestation by Ptininae (scientific name: Ptininae) in stored grain include:
- Fine silken threads and webbing binding kernels or dust, spun by larvae.
- Granular accumulations of frass and powdery feeding residues (boring dust) in pockets, seams, or on the grain surface.
- Presence of adults (imago) on the grain surface or in sievings.
- Silken, ovoid cocoons adhered to kernels, packaging, or crevices, often camouflaged with dust.
Damages
This stored‑product pest produces no distinctive kernel lesions; its impact is chiefly qualitative. In milling streams, larvae lay down silken threads (webbing) that foul flour and meal, degrading organoleptic quality and often triggering downgrading of lots to feed use. Larvae exhibit gregarious feeding, agglutinating multiple kernels with silk into clumps that disrupt flow, screening, and cleaning operations. Its occurrence is a sanitation indicator, signaling suboptimal hygiene and housekeeping in bins, transfer points, and processing lines.
Environment
Ptininae (spider beetles) favor dark, undisturbed grain stores—silos and granaries—with accumulations of broken kernels, grain dust, and frass. Cool–moderate temps, elevated relative humidity, and sheltered crevices promote colonization and cryptic infestation.
Infested products
Maize semolina, wheat semolina, bran, seeds, spices, grain dust, fish meal, warehouse sweepings, flour, ground oats and barley, oat flakes, rye.
Life cycle
Ptininae (spider beetles) are holometabolous pests of stored grain. Adults colonize grain masses, then mate; females oviposit in crevices and fines. Eggs hatch into cryptic larvae that feed within and among kernels and residues, driving loss and contamination. Larvae pass through several instars before pupating in a compact cell within the substrate. Newly emerged adults disperse and reinfest. While traits vary among species and with season, ptinines generally prefer more humid environments. Many are cold‑tolerant and can reproduce at temperatures as low as 10 °C. Development time varies by species and time of year.
Geographical distribution
World.
Similar species
None.