Agriculture plays an essential role in meeting global food demand, and so effective pest control is crucial. Aphids (Hemiptera: Aphididae) are a significant problem for many crops worldwide, and cause crop losses. They are considered one of the most important groups of pests in the world. Aphid parasitoids are very important as biological agents, both for their effectiveness and their host range selectivity. This study provides a review of these groups of parasitoids and their possible role and use in aphid biological control. Two groups of primary parasitoids, Aphelinidae and Braconidae: Aphidiinae, are the main groups that can be used in the biological control of aphids. There is also a diversity of hyperparasitoids whose hosts are these primary parasitoids and therefore are likely to be detrimental to the biological control programs: Megaspilidae in the superfamily Ceraphronoidea, the following Chalcidoidea families: Encyrtidae, Eulophidae, Moranilidae, Pteromalidae, and Signiphoridae, and Cynipoidea: Figitidae: Charipinae. Records of Mymaridae emerging from aphids, while assumed to be obligate egg-parasitoids, are discussed. Dichotomous keys are provided to identify the superfamilies, families and most important genera associated with aphids.

The maritime pine bast scale, Matsucoccus feytaudi Ducasse (Hemiptera: Matsucoccidae), occurs in the western part of the Mediterranean basin and is a sap sucking insect that feeds only on maritime pine (Pinus pinaster Aiton). It causes damage in SE France and Italy, where it was accidentally introduced. In Spain information is scarce and, moreover, almost nothing is known about the predators of this species. This study was designed to determine the seasonal trends in abundance of M. feytaudi and its major predators, which might help to improve the biological control of this pest in other areas. Natural P. pinaster stands in the Valencian Community (Spain) were surveyed in 2004. In addition, the seasonal trends in abundance of M. feytaudi and its natural enemies were monitored in three stands over a period of three years (2002, 2005 and 2006). The monitoring was carried by wrapping sticky tapes around tree trunks and using delta traps baited with sexual pheromone. The maritime pine bast scale was detected in all the stands surveyed. At almost all the sites surveyed, three species of predators were captured: Elatophilus nigricornis Zetterstedt (Hemiptera: Anthocoridae), Hemerobius stigma Stephens (Neuroptera: Hemerobiidae) and Malachiomimus pectinatus (Kiesenwetter) (Coleoptera: Malachiidae). The presence of M. pectinatus is noteworthy as this is the first record of this species as a possible predator of M. feytaudi. The results show that M. feytaudi, although differing in its phenology depending on the location, is univoltine in the study area. The prepupae, pupae and adults of M. feytaudi appeared between December and March in colder areas and between October and February in warmer areas. E. nigricornis nymphs are important predators of M. feytaudi, and were abundant when the scale insect (crawlers, prepupae, pupae, male and female adults) was present. The flight period of E. nigricornis and the hemerobiid H. stigma ranged from May to October. However, these flight patterns did not correlate with the presence of the different stages of the bast scale (crawlers, prepupae, pupae, male and female adults) on the surface of tree trunks. The presence of M. pectinatus in large numbers in some stands suggests it might be an important natural regulator, which helps to keep M. feytaudi populations at low densities in the areas of Spain studied. This malachiid shows a strong kairomonal attraction to the sexual pheromone of M. feytaudi and its flight activity is significantly correlated with the presence of crawlers of bast scale.

Aim of study: Eurytoma amygdali Enderlein (Hymenoptera, Eurytomidae), the almond wasp, is a new pest detected in Spain. Although the insect is present in Europe, in Spain no damage was detected until 2016, increasing substantially in the following years. The phenology of almond wasp and the natural enemies complex were investigated and the results of the parasitism rate and cultural control measures were analyzed. Area of study: Five Spanish provinces, important regions for almond production where E. amygdali causes serious harvest losses. Material and methods: Samples of different almond varieties were taken from ecological almond plots in the Spanish provinces of Valencia, Alicante, Albacete, Murcia and Cuenca. Main results: The first almond wasp eggs were observed at the beginning of May and completely developed larvae, early in July. Wasp flight occurred from mid-March to late May. Two natural enemies were associated with the pest, Pyemotes amygdali Çobanoğlu & Doğanlar (Acari, Pyemotidae), and Opilo domesticus (Sturm) (Coleoptera, Cleridae). Pyemotes amygdali parasitized wasp larvae, adult females and males, and Opilio domesticus fed on wasp larvae. O. domesticus was very scarce, unlike P. amygdali. In the plots with parasitized wasps, the parasitism rate ranged from 0.6% to 44% for P. amygdali. Our results suggest that sanitation measure was an important cultural pest control practice, because in the plantations where mummified almonds were removed, 96% of edible almonds were harvested, compared to 18% if mummified almonds were not removed from trees. Research highlights: Cultural control could be an important measure to control the almond wasp, because it allows biological conservation control, by preserving natural enemies present in the environment and avoid the negative effect of insecticides.